The use of anabolic-androgenic steroids (AAS) has reportedly reached epidemic proportions. AAS constitute a major drug of abuse in a wide variety of populations. Young people are at special risk. Yet there is lack of data regarding risk factors for AAS use, patterns of use, physical and mental health hazards, emergent pattern of illicit distribution, relationship of AAS use to violence. This research utilizes ethnography, structured and semi-structured interviews, and hair analysis to address etiological and epidemiological issues. The research will provide critically needed baseline data, as well as information and recommendations for the design of prevention and intervention programs. Over a 3 year period, this research will collect data from a cross sectional sample of 400 men and women in the Chicago area regarding: 1) frequencies, volumes, modes of ingestion, and types of AAS used; 2) extent and circumstances of needle sharing in an AAS using population; 3) concomitant use of other substances with AAS and interactive effects; 4) physical and mental health consequences of AAS; 5) vulnerabilities for AAS use; 6) sources of illicit AAS, patterns of distribution, means utilized to support use; 7) relationship between AAS use and distribution and violence; and 8) ethnographic description of body building and steroid using subcultures in urban and suburban gyms and health clubs. The only difference between this application and the previously submitted application is the change of applicant institution to the University of Illinois and the recruitment of subjects will occur in Chicago rather than New York City. Otherwise, there have been no changes in the proposed program.